1. Field of the Invention
The present invention relates to a self-supporting reactive hot-melt adhesive element comprising a one-component hot-melt adhesive, a process for its manufacture and its application and use. In addition, the present invention relates to an adhesive bonding or joining process for the permanent bonding or joining of parts or substrates.
2. Description of the Related Art
There are numerous hot-melt adhesives available. In particular in industrial applications, users routinely “tailor” or adapt these adhesives dependent on specific applications. For example, in the woodworking industry, in particular in the furniture industry, it is known to provide fiber plates with a coating, e.g. a veneer or a laminate, via adhesive bonding, wherein particularly thermoplastic hot-melt adhesives or moisture-reactive polyurethane hot-melt adhesives are used.
However, in numerous applications, the use of thermoplastic hot-melt adhesives is problematical, because these hot-melt adhesives show a low moisture and heat stability. In this regard, moisture-reactive polyurethane hot-melt adhesives show distinct improvements.
However, the disadvantage to moisture-reactive polyurethane hot-melt adhesives is that they can only be stored in complex packaging, in particular to the exclusion of atmospheric humidity, and have to be processed quickly after the packaging is opened.
By contrast, when using two-component adhesive systems, the disadvantage is that they must first be mixed prior to use and then processed quickly. In this case, the risk in particular is one of dosing errors.
The disadvantage to using hot-melt adhesives in particular is that in part very complicated melting-on and application devices are required, the operation and cleaning of which are associated with a considerable outlay of time and work.
For this reason, substrates are also routinely bonded using adhesive tape. However, the disadvantage to adhesive tapes is that they do not form as stable an adhesive bond as reactive hot-melt adhesives, and are always applied to a support element from which they must be separated before use.
WO 99/19413 describes a packaging for such a conventional adhesive tape with a support, wherein the support element in the form of sheets or strips has an adhesive layer, in particular a hot-melt adhesive layer, and the adhesive tape packaging has separate strip sections, whose adjacent edges are formed by notches, which cut through the support layer, but not the adhesive layer. The significant disadvantage to this adhesive tape is also that it must first be removed from the support layer prior to use.